Two novel glucodienoid alkaloids from Erythrina latissima seeds.

The structures of two novel glycodienoid alkaloids isolated from Erythrina latissima seeds have been established as (+)-16beta-D-glucoerysopine (1) and (+)-15beta-D-glucoerysopine (2). NOE measurements established that 1 and 2 are positional isomers. Their structures were elucidated from their 1D and 2D homonuclear and heteronuclear NMR spectroscopic data. In addition, seven known tetracyclic dienoid alkaloids were isolated and identified as (+)-erysovine, (+)-erysodine, (+)-erysotrine, (+)-erythraline, (+)-beta-D-glucoerysodine, (+)-8-oxoerythraline, and (+)-erysotramidine.